Dumbbell



FIG. 1 is a top, front, right perspective view of a dumbbell showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is rear view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a left side view thereof;

FIG. 8 is a top, front, right perspective view of the dumbbell of FIGS. 1-7, showing our new design with selected features disclaimed;

FIG. 9 is a top view thereof;

FIG. 10 is a bottom view thereof;

FIG. 11 is a front view thereof;

FIG. 12 is rear view thereof;

FIG. 13 is a right side view thereof; and,

FIG. 14 is a left side view thereof.

The broken lines immediately adjacent to the shaded areas define the bounds of the claimed design and form no part thereof. The broken lines depicting the remainder of the article show features that form no part of the claimed design. 

CLAIM The ornamental design for a dumbbell, as shown and described. 